Keli - I think that I've covered this point in my reply about Clari as a Folk Instrument. If you see any references to Barry Taylor's tunes have a look there. Apart from the fact that his versions of tunes are truly excellent, he often provides an alternative harmony line.

I have provided in the past some tips on writing a harmony of thirds using NoteWorthy Composer. It's super easy to do and is fun to play. I'll be away for a week but if you need help after that please give me a yell. Regards, John